The prologue shows a church in Guatemala in which a man and a boy, Ben Mears and Mark Petrie, are filling small bottles with holy water. When one of the bottles begins to emit an eerie supernatural glow, Mears tells Petrie "They've found us again." Knowing an evil presence is there, they decide to fight it.

The story then flashes back two years, to the small town of Salem's Lot (formally known as Jerusalem's Lot) in Maine in the United States. Ben Mears, an author, has returned to the town after a long absence to write a book about the Marsten House, an ominous old property on a hilltop which has a reputation for being haunted. Mears attempts to rent the house but finds that another new arrival in town, the mysterious Richard Straker, has recently bought it. Straker also opens an antique shop with his oft-mentioned but always absent business partner, Kurt Barlow. Meanwhile, Mears moves into a boarding house in town run by Eva Miller, and develops a romantic relationship with a local woman, Susan Norton. He befriends Susan's father, Dr. Bill Norton, and also renews his old friendship with his former school teacher, Jason Burke. Mears tells Burke that he feels the Marsten House is somehow inherently evil, and recalls how he was once traumatized inside the house when he was a child.

After a large crate is delivered to the Marsten House one night, an increasing number of the townsfolk begin to disappear or die in strange circumstances. Both Mears and Straker are initially the main suspects as they are new in town, but it becomes clear that the crate contained Straker's mysterious business partner, Kurt Barlow, an ancient master vampire who has come to the town after having sent Straker to make way for his arrival. Straker kidnaps a young local boy, Ralphie Glick, as an offering to Barlow, while Barlow himself kills local realtor Larry Crockett. The Glick boy then returns as a vampire to claim his brother, Danny, who himself becomes undead. In turn, Danny infects the local gravedigger, Mike Ryerson, who was entranced by the undead child's open eyes. Danny then attempts to prey on his schoolfriend Mark Petrie. However, Mark is a horror film buff who manages to repel Danny with a crucifix.

Slowly, the vampires spread as Mears, Burke, and Bill Norton figure out what is happening to the town and attempt to do something to stop it. They are attacked by the presumed dead Marjorie Glick (Ralph and Danny's mother) after she awakens on the mortician's table. Mark's parents are both killed by Barlow, though Mark is allowed to escape when the local priest, Father Callahan, holds him at bay. Jason Burke, however, falls prey to a heart attack following an encounter with the newly vampirised Mike Ryerson. In the end, Susan Norton and Mark Petrie are captured by Straker after breaking into the Marsten House. Mears and Dr. Norton head over to the house to destroy Barlow when they run into Mark who has managed to escape. Inside the house, Dr. Norton is killed by Straker, who is himself then killed by Mears using a pistol. Afterwards, Mears and Petrie find Barlow's coffin in the cellar and destroy him by driving a stake through his heart. They then escape from the other vampires in the cellar (the various townsfolk), and set fire to the house. However, Susan is nowhere to be found. As the house burns, the wind begins to carry the fire towards the town itself. Mears and Petrie then flee Salem's Lot knowing that the fire will drive all the other vampires from their hiding places and purify the town from the evil that has engulfed it.

The story then returns to Mears and Petrie at the church in Guatemala two years later. It quickly becomes clear that they are on the run from the surviving vampires from Salem's Lot, who have been relentlessly pursuing them. Their supplies of holy water glow whenever a vampire is nearby. Realising that they have been tracked down yet again, Mears and Petrie return to their lodgings to collect their belongings. However, once there, Mears finds Susan lying in his bed. Now a vampire, she prepares to bite him as he leans down to kiss her, but he drives a stake through her heart. Filled with grief, he and Petrie leave, knowing that vampires are still hunting them.

After Warner Bros. acquired the rights to 'Salem's Lot, the studio sought to turn the 400-page novel by Stephen King into a feature film, while still remaining faithful to the source material. Producer Stirling Silliphant, screenwriter Robert Getchell, and writer/director Larry Cohen all contributed screenplays but none proved satisfactory. "It was a mess," Stephen King said. "Every director in Hollywood who's ever been involved with horror wanted to do it, but nobody could come up with a script."[1]

Although generally the same story, the television adaptation takes several liberties with King's source novel. Many characters have been combined or merely deleted, as have certain subplots, and the character of Barlow is totally different in the miniseries than he is in the novel. However, Stephen King praised Paul Monash's screenplay and commented "Monash has succeeded in combining the characters a lot, and it works".[1]

However, much of the violence and graphic scenes in the novel had to be omitted to meet broadcast restrictions. Producer Richard Kobritz, who took a strong creative interests in his films, also added several changes to Monash's script including turning the head vampire Kurt Barlow from a cultured human-looking villain into a speechless demonic-looking monster. Kobritz explained:

“

We went back to the old German Nosferatu concept where he is the essence of evil, and not anything romantic or smarmy, or, you know, the rouge-cheeked, widow-peaked Dracula. I wanted nothing suave or sexual, because I just didn't think it'd work; we've seen too much of it. The other thing we did with the character which I think is an improvement is that Barlow does not speak. When he's killed at the end, he obviously emits sounds, but it's not even a full line of dialogue, in contrast to the book and the first draft of the screenplay. I just thought it would be suicidal on our part to have a vampire that talks. What kind of voice do you put behind a vampire? You can't do Bela Lugosi, or you're going to get a laugh. You can't do Regan in The Exorcist, or you're going to get something that's unintelligible, and besides, you've been there before. That's why I think the James Mason role of Straker became more important."[1]

”

Other changes by Kobritz included having the final confrontation with Barlow in the cellar of the Marsten House whereas in the book it is in the basement of Eva Miller's boarding house, a concept Kobritz felt "Just doesn't work. I mean, from a point of sheer construction in a well-written screenplay, he's got to reside in the inside of the Marsten House. He's a major star in the picture - the third or fourth most important character - he's got to be there. It may have worked in the book, but not in the movie." Susan's death was also moved to the climax, to give her death "more impact and provide the film with a snap ending."[1]

On playing Ben Mears, David Soul said "I cleaned up my speech pattern a little bit. I sound like a writer, a man who's at home with words."

For the roles of Richard K. Straker and the vampire Kurt Barlow, James Mason and Reggie Nalder had been on producer Richard Kobritz' "wish list".[2] Kobritz sent Mason a copy of the script, who loved the part and his wife, Clarissa Kaye-Mason, was also cast as Marjorie Glick.[1] However, Nalder was less impressed. "The makeup and contact lenses were painful but I got used to them. I liked the money best of all."[3]

Salem's Lot does not rely on the same kind of dynamics as The Texas Chainsaw Massacre. "This film is very spooky - it suggests things and always has the overtone of the grave. It affects you differently than my other horror films. It's more soft-shelled," director Tobe Hooper explains. "A television movie does not have blood or violence. It has atmosphere which creates something you cannot escape - the reminder that our time is limited and all the accoutrements that go with it, such as the visuals."[1]

Although Salem's Lot was aimed at television, a European theatrical release was planned from the start, which would include more violence. Two versions of the scene where Cully Sawyer threatens Larry Crockett with a shotgun were shot. In one version, Larry holds the gun barrel in his mouth, while in the mini-series the barrel is in front of his face. "They worked at a feature film pace instead of a TV pace," recalled actor Lance Kerwin on the filming. "It's really even hard to tell the flow of the film. It was a miniseries originally, then we shot a feature film version for Europe at the same time. They've edited and cut together so much."[4]

A full-scale mock-up of the Marsten House was built over a smaller house.

Unable to find a house in Ferndale that resembled the Marsten House from the book, an estimated $100,000 was spent on constructing a three-story facade over an already-existing house on a hillside, overlooking Ferndale and the Eel River Valley. Designed by Mort Rabinowitz, it took 20 days to build. Another $70,000 was spent on constructing the interior set of the house which proved even more difficult for designer Rabinowitz,[1] who also designed the building of Straker's antique shop and the small village in Guatemala where the beginning and end of the miniseries is set.[1]

The vampire make-up involving glowing contact lenses were invented by Jack Young. According to Tobe Hooper, the make up on actor Reggie Nalder would constantly fall off, as well as the fake nails, teeth and the contact lenses would go sideways.[5] The contact lenses could only be worn for 15 minutes at a time before they had to be removed to let the eye rest for 30 minutes.[1]

The vampire levitations were accomplished by placing the actors on a boom crane instead of traditional wires, "We didn't fly our vampires in on wires, because even in the best of films you can see them," producer Richard Korbitz explained. "We wanted to get a feeling of floating. And the effect is horrific, because you know there are no wires. It has a very spooky, eerie quality to it."[1] The levitation sequences were also shot-in-reverse to make the scenes more eerie.[1]

With producer Richard Korbitz wanting "a good, atmospheric, old-fashioned, Bernie Herrmann-type score", the score was composed and conducted by Harry Sukman, whom Korbitz described as "a former cohort and protege of Victor Young".[1] It was the composer's last work before he died in 1984. Although the score has not had an official release, bootlegs have surfaced on the net for download and eBay.[6][7]

Writer Bryan Fuller stated that the scene where a character is impaled on a deer's antlers in Salem's Lot inspired him to do a similar scene in his 2013 TV series Hannibal because the original scene frightened him so much as a child.[9]

Salem's Lot originally aired on CBS on November 17 and 24 of 1979 in two 2-hour segments. The following year, CBS aired an edited version of the miniseries in one 3-hour segment. NAL/Signet Books also published a paperback tie-in of the novel which included "8 pages of blood-chilling photos".

A 112-minute edit of the miniseries was subsequently given a theatrical release in Europe. The theatrical cut of Salem's Lot features different musical cues, alternative scenes, and deletes many scenes, including the prologue and epilogue with Ben Mears and Mark Petrie in Guatemala as well as Susan's fate.

The theatrical cut also aired on cable television and was titled Salem's Lot: The Movie for its VHS release. It was later released alongside A Return to Salem's Lot on VHS as a "Movie Double Feature". Warner Bros. eventually released the full-length miniseries on to VHS, as well as on DVD. The DVD release includes all of the extra scenes from the theatrical version, except the alternative scene of Larry Crockett putting Cully Sawyer's gun in his mouth.

Salem's Lot has received generally positive reviews. Review aggregate website Rotten Tomatoes reports 82% of critics gave the movie positive write-ups based on 11 reviews, with an average rating of 6.4/10.[10] British film criticMark Kermode has called it "very scary"[11] and "one of the very best screen adaptations of a Stephen King novel to date."[12]Helen O'Hara of Empire Magazine gave the film three out of five stars.[13] American critic Leonard Maltin called it "A well-made hellraiser."[14]Time Out praised "Hooper's fluid camerawork, creepy atmospherics, and skilful handling of the gripping climax."[15]Salem's Lot was also placed on Time Out's list of best vampire films.[16]The Science Fiction, Horror and Fantasy Film Review called it "one of the most underrated of all King adaptations".[17] Brian McKay of eFilm Critic wrote "Although I'll admit it is incredibly dated, it still manages to be thoroughly creepy."[18]

A sequel television series, intended to air on NBC, was originally planned. The series was to be produced by Richard Korbitz and involved Robert Bloch, and was set to continue the vampire hunting actives of Ben Mears and Mark Petrie, though it was ultimately never made.[27]

In a 1989 Fangoria interview, actor Reggie Nalder acknowledged to have spoken with production people about a sequel to Salem's Lot, but nothing came out of it.[2] In 1987, a loose sequel named A Return to Salem's Lot was released, directed and written by Larry Cohen. The sequel used the poster art from the original depicting Nalder as Kurt Barlow, although the film features neither the character nor the actor.[2]